It says that the answer is 11, for n=3 and n=8. However, with n=8, the largest angle is 240˚, which clearly makes the polygon concave, instead of convex! Shouldn't the answer just be 3? I'm so confuzzled here.

I double checked the wording this morning and we have updated the problem to have $3$ as the correct answer. The winners list has been updated to reflect this change. (This update did not remove any winners, only added some winners.)

Thank you for your feedback and we hope to see you again for the November competition!